Carroll will spend up to $50,000 in the next fiscal year to remove damaged ash trees from city property - part of a move to prepare for the seemingly inevitable invasion of tiny Asian beetles that could wipe out the vast majority of the state's ash trees.

The emerald ash borer is thought to have been brought from Asia in shipping crates in 2002 and has since spread to 21 other states, including five counties of eastern and southern Iowa. It's unclear when the beetle will reach Carroll County, but it could take years.

The beetles' larva feed just beneath the trees' bark and cut the flow of nutrients to their canopies, usually killing the trees.

Cities across Iowa have wrestled with whether to preemptively cut down some of the trees to spread the cost of removal - which will likely be hundreds of thousands of dollars for Carroll - over an extended time period.

For now, the city has allocated $50,000 of its $17 million total budget for tree removal for fiscal year 2015, which starts July 1. The budget is expected to be finalized by the city council in the coming weeks.

The beetle battle "is something we know is going to be happening in Carroll, so here's some money we can allocate to have something to start working with," said Jack Wardell, the city's parks director. "The trees of that species that are damaged now should be taken out."

Wardell said city workers will take stock of the town's ash trees in parks, the municipal golf course, the city cemetery and rights-of-way before any trees are felled and replaced with other tree species that the city grows in a nursery north of Graham Park.

Public Works Director Randy Kraul has said that his workers will chart the ash trees near streets in town with the help of Global Positioning System (GPS) satellites this spring.

Other cities, such as Des Moines, have developed multi-year plans to preemptively cut down healthy ash trees, but Wardell said there is no such plan yet for Carroll.

Chemicals exist to help protect the ash trees from the beetles, but it's unclear how effective they are.

Carroll city leaders aggressively fought Dutch elm disease in the 1960s and '70s - spraying the insecticide DDT on the tops of the city's elm trees from helicopters - with little effect. The fungus, which was spread by another species of beetle, killed nearly all of Carroll's roughly 4,000 elms.